The calls for Tennant to run amplified steadily throughout the year, Puccio said.
"The support and the calls and the recruiting that we have gotten from the voters across the state, I have never seen anything like this," Puccio said Friday afternoon.
"The recruiting has just ramped up so much for the people in West Virginia to get her to run."
Democratic political adviser Mike Plante said there is no real advantage for Tennant in delaying an announcement any further.
Plante, who's helped on numerous Democratic gubernatorial and national campaigns, said he hasn't spoken recently with Tennant or anyone who might know her plans. In his opinion though, it would have been more important for Tennant to announce earlier if there were a crowded primary field.
Announcing now could also potentially scare away any other Democrats considering a bid, Plante said. Attorney Mike Callaghan, who unsuccessfully challenged Capito for Congress in 2006, told the Daily Mail in August he was still considering running for Senate. He did not return a phone message Sunday.
Any Democrat planning a Senate campaign enters the race facing a considerable financial challenge: in July the Capito campaign announced it had nearly $3 million on hand, and that number will presumably rise when third quarter fundraising is announced next month.
Puccio expects a combined $12 million to $14 million spent for both candidates in the race. He thinks Tennant has the ability to raise a great deal of money in a short amount of time.
"Obviously, $3 million is a significant amount of money for an opponent to have," Plante said.
"It's not insurmountable and I think the money that's out there, on the Democratic side, has been waiting in search of a creditable candidate. Secretary Tennant getting in the race gives Democrats a credible, strong Democrat to get behind."
Plante agreed with Puccio that Tennant can bring in a large amount of money in a short amount of time.
Capito has shown the ability to raise money and win, Plante said. She's never run a statewide campaign though, and none of Capito's challengers have started with Tennant's statewide name recognition, he said.
Before winning the 2008 secretary of state election, Tennant had a long career as a television newsperson. Working as an anchor and reporter in both the Clarksburg and Charleston television markets introduced Tenannt to people all over the state, Plante said.
Tennant is also the first woman to serve as the Mountaineer mascot for West Virginia University, a role that's also provided her with a considerable amount of attention.
Nationally, the race to replace Rockefeller is already on the radar of political pundits.
The Fix, a political blog for the Washington Post, lists it as the top race for 2014. Political analyst Larry Sobato called the seat "likely Republican" while the Rothenburg Report says it "leans Republicans."
Before any potential face-off, both Capito and Tennant still need to win their party's nomination in the primary election. If both did, it would mean West Virginia would elect its first female senator.